Sentence Correction

It was at the American School for the Deaf that influences from both French Sign Language and various "home sign" systems would interact, intermingle, and what would become American Sign Language was born.

(a) what would become American Sign Language was born
(b) give birth to what became American Sign language
(c) what would become American Sign Language was given birth
(d) and American Sign Language, or what would eventually become it, was born
(e) American Sign Language was birthed

OA is B
CAn an Expert expatiate on this OA? Thanks.